This invention relates generally to tools and devices for opening fasteners and more particularly to devices for opening snap fasteners. Snap fasteners comprise a base which is fixed to a material or surface by a rivet, screw or other holding device, and a second mating element or cap which can be removably snapped onto the base. The cap has an expandable slip ring which holds the cap fast to the base.
Snap fasteners are used for covering the open portions of boats, truck beds, or trailers, with a heavy duty fabric weatherproof material such as canvas or tarpaulin. Snap fasteners are also used in the manufacture of clothing with coats, britches and the like.
The coverings are usually removed by pulling on the fabric at the snap to release the cap from the base. Tugging at the material to open the snap fasteners is sometimes quite difficult and can result in the breakage of fingernails, particularly in the case of women. After repeated openings, the tugging also results in damage to the fabric or material to which the snap fastener has been applied.
U.S. Pat. No. 5,079,791 (Grech) discloses a tool for unsnapping snap fasteners and reattaching snap fasteners. The tool consists of a straight handle. At one end of the handle and extending at an angle to the handle is a wedge-shaped unsnapping end which is slid between the fastener base and cap. The wedge end has a recess, between two prongs, which has sloping sides to provide lift against the underside of the fastener cap for removing the cap. Furthermore, when the fastener caps are difficult to remove, pressure may be applied to the handle to pry the fastener upwards. The other end of the handle is used for reattaching the cap of the snap fastener to the base.
Other types of prying devices are disclosed in U.S. Pat. No. 2,811,061 (Radovich) for removing the lids of film cartridges; and in U.S. Pat. No. 4,520,696 (Wolze) for opening champagne bottles.
There is a need for a snap fastener opener which is small, light and portable and which is simple and easy to manufacture and can be easily carried on a key chain and in which the shape of the opener provides additional upward force against the cap of the fastener to assist in the opening of fasteners which are difficult to open.